Not knowing Aramaic or Syriac, and considering that as you say, a fair amount of words in the Qur'an are obscure in the extreme, I can't really comment much on his alternative readings (though it looks to me like in the famous Surat al-'Alaq, the only change he made was to claim that 'alaq should mean "clay"? He can't suggest an alternative reading for the word there, at least not for the consonants... and the rest of the two versions you cited were essentially identical, or at least just two different interpretations of the text as it stands.)

The Islamic stance on the creation (or, more accurately, non-creation) of the Qur'an has been rather silly ever since the decline of the Mu'tazila and the heroic behaviour of that idiot Ibn Hanbal. Post-medieval mainstream Sunnism has been characterized by a rather anti-intellectual streak, honestly, or at least anti-critical thinking, with a number of obvious exceptions. There are so many dogma's that casting doubt on the most fundamental one of all is inevitably seen as a direct attack on the heart of the religion. Perhaps if they hadn't raised hadith to the completely undeserved status it has, or spent so many lives trying to make sense of it, they'd be more open to critical analysis of the Qur'an itself. And perhaps if the Mu'tazila had carried the day instead of the "ask no questions" brand of Sunnism... but well, that kind of remarks doesn't help very much.